1. Field of the Invention
The present invention relates to a lens-barrier device for a camera including a video camera, an electronic still camera, a photographic camera, and so forth. In particular, the present invention relates to a lens-barrier device for a camera provided with a lens barrier for protecting a taking lens.
2. Description of the Related Art
Cameras provided with a lens barrier for protecting a taking lens are disclosed in Japanese Patent Laid-Open Publication Nos. 9-68738 and 2000-155355. The lens barriers disclosed in these Publications are manually moved between a closed position for covering the taking lens and an open position for exposing the taking lens. Since the whole operation for moving the lens barrier to the open position is manually carried out, it is likely to miss a shutter chance. Moreover, a camera body is provided with a rail groove for movably supporting the lens barrier so that the rail groove appears on an outer surface of the camera to disfigure the camera.
In order to deal with the above disadvantages, it is desired that the camera is provided with a spring for assisting the lens barrier in moving to the open position. Further, it is desired to provide the rail groove on the lens barrier. However, if the rail groove is provided on the lens barrier, the lens barrier is likely to have a large size. As to the spring for urging the lens barrier toward the open position, if the spring is attached to the camera body, the exterior of the camera is marred. The reason for this is that the camera body needs a slot used for moving a connection member, which connects one end of the spring to the lens barrier. In view of this, the spring is attached to the lens barrier. However, in case the spring is a tension spring, it is impossible to contain the spring inside a contour of the lens barrier. Thus, it is desirable to employ a compression spring.
When the lens barrier is urged by the spring toward the open position, a locking mechanism is necessary for locking the lens barrier against the spring when the lens barrier is set to the closed position. In general, the well-known locking mechanism includes a lock release button or the like provided on the camera body. By handling this button, the locking mechanism is released.
Meanwhile, in the case the lens barrier is urged by the compression spring toward the open position, the compression spring intervenes between the lens barrier and the camera body. In this case, it is necessary to urge the lens barrier from the closed position toward the open position even when the lens barrier is set to the open position. By the way, when the lens barrier is set to the closed position, the compression spring is more compressed in comparison with the state in that the lens barrier is set to the open position. The compression spring has a limit of length at the time of compression. Thus, there is a shortcoming that a movement amount of the lens barrier is reduced by an amount corresponding to the limit length of the compression spring.
Further, when the lock release button is separately provided, production costs increase due to an interlocking mechanism for connecting the lock release button to the locking mechanism. In addition, since the interlocking mechanism is built in the camera body, there arises a problem in that a size of the camera body becomes larger.
In view of the foregoing, it is a primary object of the present invention to provide a lens-barrier device for a camera in which an exterior of the camera is prevented from being disfigured.
It is a second object of the present invention to provide a lens-barrier device for a camera in which a movement amount of a lens barrier increases.
It is a third object of the present invention to provide a lens-barrier device for a camera in which it is possible to downsize the camera.
It is a fourth object of the present invention to provide a lens-barrier device for a camera in which production costs of the camera may be reduced.
In order to achieve the above and other objects, the lens-barrier device according to the present invention comprises a mechanism for locking a lens barrier at a closed position, where a taking lens is covered therewith. After moving the lens barrier from an open position, where the taking lens is exposed, to the closed position, the lens barrier is further moved toward a lock switch position so as to pass across the closed position. In doing so, the lens barrier is locked at the closed position. Under this state, the lens barrier is moved again to the lock switch position to release the lens barrier locked at the closed position.
The lens-barrier device comprises another mechanism for urging the lens barrier toward the open position. This urging mechanism is constituted of compression springs, a press member, and a slider. The compression spring urges the lens barrier toward the open position. The press member abuts on one end of the compression spring, and is moved together with the lens barrier. The slider abuts on the other end of the compression spring, and is moved within a predetermined range together with the lens barrier when moving the lens barrier from the closed position to the lock switch position.
In the present invention, the locking mechanism locks the lens barrier by pushing it toward the lock switch position after moving the lens barrier from the open position to the closed position. Moreover, the locking mechanism releases the lock of the lens barrier by pushing the lens barrier again from the closed position to the lock switch position. It is possible to decrease production costs and to reduce a size in comparison with a case in that a lock release button is separately provided.
Further, the slider is provided so as to move together with the lens barrier when pushing the lens barrier from the closed position to the lock switch position. Consequently, a movement amount of the lens barrier is adapted to increase.